Soldiers marching across the bridge in Athlone prior to the handover of Custume Barracks
|In use||1691 - present|
|Garrison||6th Infantry Battalion, Irish Army|
The barracks were built originally as temporary accommodation for cavalry and infantry units in 1691. The barracks are named after a Sergeant Custume, who defended the bridge from the forces of King William III during the 1690 Siege of Athlone. The barracks were taken over by forces of the Irish Free State in 1922 and served as the headquarters of 4th Western Brigade until the brigade was disbanded and is now part of 2 Brigade which is headquartered from Cathal Brugha Barracks in Dublin. The barracks remains the home of 6th Infantry Battalion as the lead unit, and 2nd Brigade Artillery Regiment and detachments of 2 Engineer Company and the Medical Corps.
During the Cold War, there were contingency plans in place that, in the event of a nuclear exchange, cabinet ministers, senior civil servants and military advisers would use an underground nuclear bunker at Custume Barracks. The bunker was equipped with a command and control centre with communications equipment - which had a hotline to the British government in Whitehall - a map room pointing out important areas for protection, kitchen, bedroom and bathroom facilities to accommodate up to 100 persons.
In 1968 a larger nuclear bunker, housing the Integrated National Control Centre (INCC), was planned for Athlone. This was planned to have capacity to accommodate and feed up to 300 people for a month, and allow the Government to continue in the event of a nuclear emergency. The Department of Defence and the Office of Public Works (OPW) drew up secret plans for a larger 20,000 sq ft (1,900 m2) underground bunker to include operations rooms, message centre, broadcasting studio, kitchens, offices, committee rooms, sleeping accommodation and 100,000 imperial gallons (450,000 l; 120,000 US gal) of uncontaminated drinking water. The plans for this new bunker never went ahead.